U.S. Department of EnergyEnergy Efficiency and Renewable EnergyFederal Energy Management Program

United StatesEnvironmentalProtection Agency

L a b o r a t o r i e s f o r t h e 2 1 s t C e n t u r y :

B e s t P r a c t i c e G u i d e

COMMISSIONING VENTILATED CONTAINMENT SYSTEMS IN THE LABORATORY

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Introduct ionVentilated containment equipment has commonly been delivered and installed as off-the-shelf selections, consid-

ered state of the art by default if not by superior design. However, with advancing technology of ventilated contain-ment systems (VCS) and with heightened concern over material hazards, environmental protection, and energy conservation, equipment efficacy must be assured. Consequently, commissioning has become an essential discipline for the effective construction and operation of laboratory facilities. Additionally, a well-implemented commissioning plan can help pave the way to Leadership in Energy and Environmental Design (LEED) certification, as established by the U.S. Green Building Council.

The concept of commissioning has been shaped over time by design teams to fit their particular time, place, and set of needs. It has been viewed as any set of inspection and testing activities somewhere between planning and end-use

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operations. To provide an operational definition: “Commissioning is everything you do to make certain that you get the performance you asked for in a given facility design.”

This Best Practice Guide does not cover comprehen-sive building commissioning, but focuses on the special-ized approaches required for VCS, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. The sys-tem typically begins with the dampers that modulate air supplied to the laboratory and ends at the top of the exhaust stack. Everything in between is considered part of this system: supply-air diffusers, ventilated enclosures, exhaust valves, fans, controls and algorithms, and related items integral to this equipment.

Many resources exist for understanding and imple-menting commissioning activities (see References and Resources). This guide is one in a series of best practices for laboratories produced by Laboratories for the 21st Century (“Labs 21”), a joint program of the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). Geared toward architects, engineers, and facility managers, these guides provide information about technologies and practices to use in designing, constructing, and operating safe, sustainable, high-performance laboratories.

A Spectrum of Vent i lated Containment Equipment

The contemporary laboratory may be a simple instal-lation of one ventilated enclosure or may contain multi-ples of the entire range of containment devices in use today:

• Fume hoods

• Custom ventilated enclosures

• Articulated arm exhausts

• Balance enclosures

• Downdraft tables

• Slotted backdraft hoods

• Biological safety cabinets

• Gloveboxes and glovebags

• Canopy hoods

Each device has multiple types designed for a specific purpose with specific performance criteria that can only be determined by those familiar with the characteristics of the materials and the operation. Ideally, each device type will be tested individually and as it interacts with other equipment in the system. This customized complexity is the primary reason that VCS commissioning must begin with the design process.

Bringing Together Essent ia l Personnel

It is unlikely to find a single commissioning company that has all the expertise necessary for coordinating com-prehensive building commissioning and that is also skilled with the intricacies of VCS commissioning. Creating a multidisciplinary team with experience in engineering design, construction, and facility operations is essential. The initial commissioning team should combine the archi-tectural and enginering (A&E) firm with in-house staff, forming a group that embraces all the needed talents. This core team can put together the initial plan, turning to a larger group for review and feedback. Consider including these resources:

Internal s taf f :

• End users

• Engineering

• Health, safety, and environmental

• Project management

• Maintenance

External Staf f

• A&E firm

• Commissioning agent

• Testing consultants

Several key parties can be identified later: the equip-ment manufacturers and vendors, general contractors and their subcontractors, and the testing, adjusting and balanc-ing (TAB) contractors; however, based on past experience the commissioning agent and testing agents should be hired early on. The commissioning firm should be experi-enced in laboratory building startup, and the testing con-sultants must have documented experience with the specialized equipment and knowledge required to be pro-ficient with VCS. Interviews help to evaluate verbal and people skills, but should be backed up by references and work samples. Commissioning and/or testing agents may be from internal staff, but it is rare to have staff with broad experience in VCS commissioning.

The prospective testing consultant should fully com-prehend equipment design: the aerodynamics of ventilat-ed enclosures, including airfoils and baffles, the subtle effects of shape on airflow patterns, and air-supply modifi-cations such as auxiliary air, bypass grilles, and supply dif-fusers. The consultant must understand safety, quality, and environmental equipment options and how they affect the commissioning protocol, including the benefits and disad-vantages of variable air volume (VAV) compared to con-stant air volume (CAV) air supply and exhaust. Another option is with exhaust systems, where manifold systems can reduce costs, conserve energy, and increase safety. The

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intent document. A detailed design document reflects agreements among all parties as to the valid requirements of the project that will shape later commissioning: equipment choices, such as the design opening of hoods, and performance criteria, such as average face velocity, speed of response, stability, and containment. User needs, safety/risk assessments, and environmental and energy performance requirements all fit into the mix, expressed in a set of construction drawings, a bidding package, and a well-defined commissioning plan.

1) User needs. Many laboratory applications can appear to require highly customized ventilated enclosures and systems. These drive up facility costs and should be justified by a safety/risk analysis. Most laboratory con-tainment requirements are accommodated by standard manufacturers’ models with an array of options. If a cus-tom design is genuinely required, detailed commissioning requirements for the item must be part of the design pro-cess. Other user requirements affecting commissioning include air cleanliness and temperature and humidity lim-its. Where exhaust filtration is required, criteria must be established early for appropriate filter specification and commissioning requirements.

2) Safety/risk. First, determine the nature of the risks to be managed, whether chemical, biological, or physical. Some hazards require specialized rooms, ventilation sys-tems, or life-safety systems; and commissioning for excep-tionally hazardous materials may need substance-specific monitoring during equipment operation. If exposure lim-its do not exist to determine pass/fail criteria, reasonable criteria must be established so that the manufacturer has a target to aim for. This type of testing may be expensive and should be prescribed judiciously. Testing with

consultant should be conversant with testing standards: face velocity range, criteria for flow visualization, and tracer gas or particle-counting challenges. Particularly, the consultant should be able to discuss the variables of static vs. dynamic conditions, sash positions, and test duration. The consultant should be able to extrapolate from these standard fume hood tests to recommend procedures for other ventilated enclosures.

Key E lements of the Commissioning Plan

A commissioning plan that begins in the earliest stag-es of a project leads to an orderly and effective succession of events. A complete plan identifies all equipment and systems requiring commissioning, with performance test-ing methods to be used for each component, along with parameters for acceptable performance. The documenta-tion will include these items:

• All equipment submittals required to support the commissioning process

• Requirements for training of the operations and maintenance personnel

• Expected owner/user manuals

• Requirements for process sequence and system operation manuals

• Sample formats for reports and other documentation

• A detailed schedule for when various commissioning operations will occur

Commissioning with in the Phases of a Project

In the broadest strokes we can discuss the progress of a sound commissioning plan during a three-stage timeline: Design, Deliver, and Sustain.

Design. End-users, A&E firms, industrial hygiene and safety personnel, engineers, and management should all be included in the design stage. This first phase will result in a formalized expression of a facility concept, which should be manifested in a design profile or a design

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Figure 1. A large custom enclosure requires specialized commissioning criteria.

Commissioning for LEED

The commissioning plan can also facilitate LEED certification. The LEED prerequisite fundamental building systems commissioning mandates specific steps that exemplify a good commissioning plan even when certification is not planned. The LEED program offers additional credit for “Enhanced Commissioning” for in-depth oversight during the design and submittal process to catch potential problems. Check www.usgbc.org for details.

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surrogates (such as sulfur hexafluoride) should be done whenever possible, but safety-critical operations may require actual operational data collected by a continuous monitoring system.

The best designed ventilated enclosures are still dependent for their effectiveness on the environment in which they are installed. A containment and ventilation system is designed based on a projected interaction of a number of personnel using specific equipment and operat-ing in concert with a correctly designed air-handling sys-tem. The number of people in a room often determines the number of ventilated enclosures per room, which in turn determines the total airflow required. Depending on the extent of containment required and the types of ventilated enclosures used, excessive air changes can make attaining the containment criteria impossible, calling for a change in basic assumptions of building size or population. Reliance on incorrect containment criteria leaves the project suscep-tible to extensive failures and cost overruns.

A corollary of the airflow volume is velocity, a surpris-ingly overlooked design factor. Even if the air-change rate is not excessive, too great an air-supply velocity has dele-terious effects on containment. Commissioning criteria will guide the designers in distributing air at the proper location and velocity. A higher velocity can be tolerated if air-supply diffusers are positioned away from the enclo-sure. A rule of thumb is no closer than five linear feet (1.5 m) from the face of the enclosure. It is preferable, however, that air-supply velocities be kept as low as possible. The European recommendation, for reasons of comfort, is a velocity not to exceed 40 fpm (0.2 mps) at 2 m above the floor (see ANSI Z9.5-2003: supply air velocity should not exceed 50% of face velocity at head height; or NFPA 45-2004: ideally less than 30% of face velocity). Another air-delivery precaution is to avoid windows and doors that open to natural air currents that wreak havoc with containment. The amount of return air, if any is permitted, is crucial. Most laboratories should be 100% once-through air, but if a risk assessment allows it, a heavy energy bur-den can be reduced by prudent recirculation or transfer-ring supply air from office areas to adjacent labs.

A risk assessment will match the appropriate biosafe-ty cabinet (BSC) class and type to the actual hazard. Contributing factors are localized particle cleanliness, cleanability, and recirculation vs. external exhaust. BSCs fall under the jurisdiction of the National Sanitation Foundation (NSF) (see NSF Standard 49, Class II (Laminar Flow) Biosafety Cabinetry). The commissioning protocol should apply criteria from this standard, but exceptional situations, such as BSCs in aseptic environments, may call for added testing.

3) Environmental and energy performance. Establish these criteria for the proper level of emissions control. Vapor control systems to consider are the condensers, scrubbers, and adsorbers. For particulate control, consider cyclones, frame or cartridge filters, bag houses, or electro-static filtration.

High efficiency particulate air (HEPA) filters, devel-oped for nuclear and biological applications, are often the default choice for exhaust filters, but many particulates are not in the low micron size categories necessitating HEPA filtration. Adequate filtration can often be achieved with filters in the 65% to 85% efficiency range (ASHRAE 52.1/MERV 11-13), thus reducing both equipment and energy costs. Filtration will increase the system static pressure and therefore significantly increase the horsepower neces-sary to drive the system. Conduct a risk and engineering assessment to match the filtration level to the hazard level. Without this evaluation, the sizing of the system, the pres-sure rating of system components, and even airflow vol-umes can be incorrectly specified. The type of filter will drive commissioning requirements, so early filter deter-mination is essential (see: Low-Pressure-Drop HVAC Design for Laboratories).

High velocity discharge and/or manifold exhaust sys-tems may also be needed to prevent reentrainment of lab exhaust into the building or into the air intakes of neigh-boring buildings. You may want to enlist the aid of a firm that can conduct air emission modeling or wind tunnel testing as a precommissioning screening process. When the site is complicated by numerous buildings or complex topography, wind tunnel testing will provide the most accurate and usable data. Depending on the criticality of the application, on-site tracer gas testing may be needed at the time of commissioning to verify that the wind-tunnel design has met actual emissions criteria. On-site testing as part of the commissioning process can be heavily impact-ed by weather conditions. Keep in mind the possible tim-ing of the commissioning so that if weather could be a significant factor, provisions are made in the project sched-ule to accommodate delays and cost overruns that could occur (see: Modeling Exhaust Dispersion for Specifying Acceptable Exhaust/Intake Design).

A sequence of operations document, prepared during the detailed design phase, sets forth an agreement on how even the most complex containment system will operate under varying conditions, from normal operation to auto-matic and manual flow setbacks such as alarms, spills, and power loss. Beyond the proper documents, such as the design intent and listing of systems to be commissioned, design-phase commissioning should include planning for quality assurance. Development of a basis of design docu-ment will serve to codify the criteria that have been dis-

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cussed. Take sufficient time to review the ventilation system design with involved staff or consultants, and ensure that the A&E firm has fully and accurately includ-ed the commissioning criteria in the bidding and construc-tion documents.

Deliver. During the delivery stage, verification and testing take place. Factory Acceptance Testing (FAT) to evaluate the equipment performance is conducted at the manufacturer’s or a third-party’s site. Some protocols may include challenge tests: the walk-by, which simulates worker movement, the fan-forced draft, which reflects room air influences, and thermal loading, which tests the enclosure’s capability to overcome convective currents.

Receipt verification ensures that the specified design intent has been fulfilled, and installation verification makes certain that equipment and systems are physically installed in the correct manner, which may be a quick check against blueprints or require scrutiny where correct installation is exacting.

A checklist is an effective tool for ensuring quality installations. This list itemizes all piping, conduits, duct-work, and accessory fittings needed for full design func-tioning of the ventilated enclosure. The list first communicates the expectations of the installation, and, second, helps to evaluate the installation. Where an intri-cate collection of piping, conduit, ductwork, and other utilities must be coordinated, an on-site mockup can serve as a model for correct and consistent installation. The mockup should be identified in the commissioning plan, specifications, and drawing notes, and then constructed as soon as possible. Typically it can be retained for use in the final construction.

As the facility progresses to more advanced stages of construction completion, both operational testing and startup begin. Some consider these separate operations, but they are tasks that are best combined. The commis-sioning firm should facilitate startup and testing. The ven-tilated enclosure and controls manufacturers will verify that fans, dampers, and other components are functioning properly. Components not functioning correctly will be referred back to the electrical and mechanical contractors for corrections. The TAB contractor must be part of these startup operations, making certain that adequate air is provided for startup operations even though heating ven-tilation and air-conditioning (HVAC) system balancing is just beginning.

Some commissioning procedures may need adjust-ment for setup conditions. Deviations from design, such as duct routing, equipment substitutions, or control limita-tions, may require testing adaptations. Architectural, engi-neering, safety, and commissioning personnel should work as a team when specialized validation methodolo-

gies are needed to accommodate irregularities in installation.

Once the building is balanced, the stability of the sup-ply and exhaust systems must be assessed. The best meth-od for collecting this data is through the Building Management (or Automation) System (BMS). Static pres-sure data from the supply and exhaust manifolds should be logged once per minute for at least 72 hours to discover any problems (see ASHRAE 110-2006 for procedures or confer with the testing consultant, BMS contractor, or con-trols manufacturer). If an HVAC system is found to be unstable, e.g., exhibiting large swings in pressure, oscilla-tion, or hunting, the cause must be corrected before per-formance testing begins.

Next, the supply and exhaust flow control system is tested for functionality and stability. This involves real-time monitoring of room pressure for a specified time while VAV components (e.g., fume hoods, temperature-controlled general exhaust) are operating. Now that the system has been checked for adequate control, the perfor-mance testing of the ventilated enclosures can commence.

The most common ventilated enclosure in the lab is the chemical fume hood, which relies on directional air-flow at a specified velocity to capture contaminants. A face velocity of 80 ft/min to 120 ft/min was long accepted as assurance of containment for the fume hood, but this is now looked on as only a first check, to be followed by an array of tests. The procedure that has guided fume hood testing in the U.S. since 1985 is the ASHRAE 110 Method of Testing Performance of Laboratory Fume Hoods (see ASHRAE 110-2006). This document recommends a testing regimen, without setting absolute pass/fail levels, recog-nizing that testing criteria must be appropriate to the intended usage. Another standard, ANSI Z9.5 (see ANSI Z9.5-2003), provides useful guidance on establishing per-formance criteria for VCS.

Fume hood testing is currently based on any of four procedures, the American ASHRAE 110, the EN14175 for European use, the Australian AS/NZS22438 (2001), and the Canadian Standards Association (CSA) Standard Z316-04. These documents provide a foundation both for factory acceptance testing and for as-installed perfor-mance testing. Requirements vary among these standards, but all fairly agree on a basic course of testing, except for the Australian standard, which omits tracer gas testing.

A testing sequence is recommended that immediately reveals any major problems and proceeds through a range of increasingly precise analyses: beginning with face velocity, next low and then high volume flow visualiza-tion, and finally tracer gas testing. Any serious failure in this sequence according to established project criteria would call for remediation and retest before continuing.

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nance testing or for comparison following laboratory modifications. Random testing of multiple, similar instal-lations is a tempting money and time saver, but a baseline of performance data should be established for each piece of equipment. However, random testing of VAV systems for speed-of-response can be a reliable indicator across systems.

Widely recognized procedures do not exist for venti-lated enclosures other than benchtop fume hoods or BSCs, but testing for other enclosures should be similar. Appropriate test protocols can be developed by adapting procedures for the standard fume hood and/or BSC. Because of their unique customization, downdraft tables, gloveboxes, and glovebags should be tested according to specifications developed in conjunction with the manufac-turer, the testing consultant, and the in-house engineering and industrial hygiene staff.

A performance testing protocol should include all details to preclude later disagreements regarding 1) who will do the testing, when and where, 2) a list of each item and all tests to be conducted for each, 3) pass/fail criteria, 4) test results reporting, and 5) responsibility for remedia-tion and retesting.

The final step in delivery is documentation. Testing guidelines can suggest a report format or the project team can establish its own.

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yFigure 2. Flow visualization during a standard performance test.

Table 1 . Recommended Tests

TestsLaboratory Fume Hood (LFH)

Ventilated Balance Enclosure (VBE)

Custom Ventilated Enclosure (CVE)

Biological Safety Cabinet (BSC)

Local Exhaust Ventilation (LEV)

Installation inspection standard standard standard standard standardVelocity at face (plus downflow for BSC)

standard standard standard standard* good

Low-volume flow visualization (smoke/fog)

standard good good standard good

High-volume flow visualization (smoke/fog)

good N/A better N/A N/A

Tracer gasStatic test standard good** standard good** goodDynamic test good N/A better N/A N/AChallenge test good better better better better

Face velocity alarm or flow alarm standard standard good standard better

Exhaust filter integrity N/A standard*** N/A standard N/ASupply filter integrity N/A N/A N/A standard N/ADuct air flow volume good good good good standardSound level good better good standard betterLighting level better better better standard N/A

* Indirect measurement (see NSF 49 or EN12469 for specifics)

** Tracer gas testing on these devices only if they are exhausted externally.

***This is mandatory if the ventilated balance enclosure is recirculated.

N/A = Not Applicable

Table 1. indicates appropriate tests for each of the ventilat-ed enclosures listed.

Diagnostic tests may assign cause when the standard tests reveal a containment failure, possibly attributable to room air currents or the interplay of the enclosure with the building mechanical system.

Performance testing provides, first, a go-ahead for safe operations, and, second, a baseline set of data that will be used as a reference for annual preventive mainte-

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Sustain. After performance testing, training programs and maintenance procedures pave the way for an operationally and economically sustainable facility. Training is the responsibility of the facility owner, but the owner can negotiate with equipment vendors for training assistance. The lab users and maintainers must understand the design intent of the system and how to respond to prompts and alarms. Failure to train these personnel can result in wasted energy, loss of productivity, broken equipment, and even illness or injury. Responsible and proactive vendors will insist on leading an in-depth training program, which typically reduces warranty claims.

Maintenance and repair training should be part of the vendor contract documents. Staff must be trained in pre-ventive maintenance, making clear what should be attempted only by trained manufacturer’s representatives and what can be done in-house. Vendors should provide a list of critical spare parts to keep on hand and informa-tion on lubrication, cleaning, calibration and preventive

maintenance intervals. Performance testing data should be retained as a baseline reference for preventive mainte-nance procedures. The commissioning agent can help cre-ate a long-term auditing program. The in-depth system audit should evaluate preventive maintenance in regard to both safety and energy efficiency. Ongoing preventive maintenance and auditing programs should be document-ed in the commissioning manual.

A laboratory of any age that has not been commis-sioned or has undergone modifications should be sched-uled for retrocommissioning with a professional that has expertise in testing containment systems (see Retro-Commissioning Laboratories for Energy Efficiency).

Moving through the 21st Century : Issues & Innovat ion

As the art of commissioning continues to evolve, changes will result from technological advances, particu-larly in the area of ventilated enclosure testing. New and better analytical equipment will make testing faster, and it’s even possible that self-diagnostic systems could even-tually replace some baseline testing. It is unlikely though, that the fundamental commissioning tasks (e.g., verifica-tion tasks) would ever be automated. Nonetheless, as human interfacing decreases, commissioning costs should also shrink (the major cost now attributable to hourly compensation). While commissioning must encompass an array of factors, economics will always play a role. Managing costs is essential, because the more affordable commissioning can be made, the more likely a thorough commissioning will be conducted. Ultimately, it is the safety of the user that is at stake.

In terms of economics and the environment, it is also essential to minimize energy use and maximize energy efficiency. When developed and implemented in parallel with design and construction, a comprehensive commis-sioning plan will serve this purpose well. The Labs21 pro-gram provides many ideas, references, and tools for improving energy performance (see Labs for the 21st Century). Environmental Performance Criteria (EPC) spe-cifically address ventilation-related energy principles to consider in the commissioning plan.

References and ResourcesASHRAE Guideline 1-1996, “HVAC Commissioning Process,” American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Atlanta, GA: 1996.

ASHRAE Laboratory Design Guide, Chapter 14, “Laboratory Commissioning Process,” American Society of Heating Refrigerating, and Air-Conditioning Engineers, Atlanta, GA: 2001.

ASHRAE 110-2006, “Method of Testing Performance of Laboratory Fume Hoods,” American Society of Heating Refrigerating, and Air-Conditioning Engineers, Atlanta, GA: 2006.

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Figure 3. Mannequin simulates worker exposure during a tracer gas test .

L A B S F O R T H E 2 1 S T C E N T U R Y8

Laboratories for the 21st Century

U.S. Environmental Protection Agency

Office of Administration and Resources Management

www.labs21century.gov

In partnership with the

U.S. Department of Energy

Energy Efficiency and Renewable Energy

Bringing you a prosperous future where energy

is clean, abundant, reliable, and affordable.

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This publication is subject to Government rights.

DOE/GO-102008-2653

August 2008

Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 10% postconsumer waste.

ASHRAE 111-1998, “Practices for Measurement, Testing, Adjusting, and Balancing of Building Heating, Ventilation, Air-Conditioning and Refrigeration Systems,” American Society of Heating Refrigerating, and Air-Conditioning Engineers, Atlanta, GA: 1998.

ASHRAE 52.1/MERV 11-13, Standard 52.1-1992, “Gravimetric and Dust-Spot Procedures for Testing Air-Cleaning Devices Used in General Ventilation for Removing Particulate Matter,” Atlanta, GA: 1992.

AS/NZS 2243.8 (2001), “Safety in Laboratories, Part 8: Fume Cupboards.”

ANSI/AIHA Z9.5-2003, “American National Standard for Laboratory Ventilation,” American National Standards Institute, Inc./American Industrial Hygiene Association. 2003.

Bell, G.C. (April 25, 2003), “Retro-Commissioning Laboratories for Energy Efficiency,” Laboratories for the 21st Century Technical Bulletin. www.labs21century.gov/pdf/bulletin_retrocx_508.pdf.

Canadian Standards Association (CSA), Standard Z316-04, “Fume Hoods and Associated Exhaust Systems.”

DiBerardinis, Louis J., et al., Guidelines for Laboratory Design, 3rd ed., John Wiley & Sons, NY, 2001.

EN12469, “Performance Criteria for Microbiological Safety Cabinets” www.standardsdirect.org/standards/standards5/StandardsCatalogue24_view_9373.html.

EN14175 for European use, “Fume Cupboards” www.standardsdi-rect.org/standards/standards1/StandardsCatalogue24_view_11552.html.

Labs for the 21st Century. www.labs21century.gov/.

Petersen, R.L; Carter, J.J.; Cochran, B.C. (May 2005), “Modeling Exhaust Dispersion for Specifying Acceptable Exhaust/Intake Designs, Optimizing Laboratory Ventilation Rates.” Laboratories for the 21st Century. www.labs21century.gov/pdf/bp_modeling_508.pdf.

NFPA 45-2004, “Standard on Fire Protection for Laboratories Using Chemicals,” National Fire Protection Association, 2004.

NSF Standard Number 49, “Class II (Laminar Flow) Biosafety Cabinetry,” National Sanitation Foundation (NSF) International, March 16 2004.

OSHA, 29 CFR 1910.1450, “Occupational Exposures to Hazardous Chemicals in Laboratories,” U.S. Department of Labor Occupational Safety & Health Administration. www.osha.gov/pls/oshaweb/owa-disp.show_document?p_table=standards&p_id=10106.

PECI. (2006). “PECI Resource Library,” Commissioning Resources, www.peci.org/resources.html.

“Procedures for Decontamination and Decommissioning for Laboratory Buildings,” Chemical Health and Safety, 6(5), 4, 1998.

Weal, J.; Rumsey, P.; Sartor, D.; Lock, L.E. (February 2005), “Low Pressure Drop Design for Laboratories,” Laboratories for the 21st Century. www.epa.gov/lab21gov/pdf/bp_lowpressure_508.pdf.

AcknowledgmentsAuthor: Stan Lengerich, Eli Lilly and Company

Contributors and Reviewers: Bernie Blazewicz, Merck & Co., Inc. Steve Crooks, RTI International; Mike Dockery, Sui Generis Ltd.; Bob Haugen, Kewaunee Scientific Corp.; Doug Haughs, Biomedical Safety Consultants; Dale Hitchings, Safelab Corporation; Scott Moll, Affiliated Engineers, Inc.; Victor Neuman, TAC Precision Environmental Group Ray Ryan, Flow Sciences, Inc.; Rohit Saxena, Hellmuth Obata + Kassabaum, Inc.; Bernd Schubert, Tintschl Engineering; Ransom Sides, Eli Lilly and Company; Thomas C. Smith, Exposure Control Technologies; Otto Van Geet, NREL; Ralph Wrons, Sandia National Laboratories

Production: Paula Pitchford, Grace Griego, and Susan Sczepanski, NREL

For More Informat ionOn Laboratories for the 21st Century

Dan AmonU.S. Environmental Protection Agency1200 Pennsylvania Ave., N.W. (mail code 3204R)Washington, DC 20460202-564-7509amon.dan@epa.gov

Will LintnerU.S. Department of EnergyFederal Energy Management Program1000 Independence Ave., S.W. Washington, DC 20585202-586-3120william.lintner@ee.doe.gov

Best Practices on the Webwww.labs21century.gov